Use respond_to?(:to_ary) rather than is_a?(Enumerable) to detect collection-thing.

2 files changed, 5 insertions, 3 deletions

diff --git a/activemodel/lib/active_model/serialization.rb b/activemodel/lib/active_model/serialization.rb
index 4403ef060b..00cd05b7ef 100644
--- a/activemodel/lib/active_model/serialization.rb
+++ b/activemodel/lib/active_model/serialization.rb
@@ -87,8 +87,8 @@ module ActiveModel
       Array(options[:methods]).each { |m| hash[m.to_s] = send(m) if respond_to?(m) }
 
       serializable_add_includes(options) do |association, records, opts|
-        hash[association.to_s] = if records.is_a?(Enumerable)
-          records.map { |a| a.serializable_hash(opts) }
+        hash[association.to_s] = if records.respond_to?(:to_ary)
+          records.to_ary.map { |a| a.serializable_hash(opts) }
         else
           records.serializable_hash(opts)
         end
diff --git a/activemodel/lib/active_model/serializers/xml.rb b/activemodel/lib/active_model/serializers/xml.rb
index 5084298210..b78f1ff3f3 100644
--- a/activemodel/lib/active_model/serializers/xml.rb
+++ b/activemodel/lib/active_model/serializers/xml.rb
@@ -115,7 +115,9 @@ module ActiveModel
           merged_options = opts.merge(options.slice(:builder, :indent))
           merged_options[:skip_instruct] = true
 
-          if records.is_a?(Enumerable)
+          if records.respond_to?(:to_ary)
+            records = records.to_ary
+
             tag  = ActiveSupport::XmlMini.rename_key(association.to_s, options)
             type = options[:skip_types] ? { } : {:type => "array"}
             association_name = association.to_s.singularize